tweaks made while running forum with ruby 2.1.2

The changes to this file are merely fixes to bugs I found while playing around with the different tools in the forum I was running locally using Ruby 2.1.2 and Rails 3.2.16. Not really related to Ruby 2.1.2, but worth fixing.  Line 40 was throwing an exception where it could not find topics. Line 65 was not finding the correct path for the images. The thumb path was missing, so the images appeared as broken.

I should mention that what I originally did was clone, setup and run forums for cmmonline and watertechonline in my local environment. As I tried to run them using Ruby 2.1.2 and Rails 3.2.16, there were exceptions thrown related to errors in two locales: DE an RU. RubyMine allowed me to delete both files in the local copy of my dependency to this gem. After I got everything working properly in my local copy of the forums, I cloned this repo and searched for the two locale files to delete them as well and push the changes, but could not find the files in here, so I'm not sure how come they were included when I cloned and bundled forums.cmmonline and forums.watertechonline. The files are not included in the epub_community_engine or in the forums.cmmonline or forums.watertechonline repos either.

There were no tests, so what I did was setup the forums locally and try the different tools. Everything seems to work correctly with Ruby 2.1.2. At some point I thought I was having a dependency issue because uploads to certain types of files were not working (uploads are used in photos and clippings), but it turned out to be a problem with my local installation of imagemagick that was missing jpeg.